1. Field of the Invention
The present invention relates to means of fixing electronic systems to a tire. Here, the term “tire” refers to any type of elastic casing, whether it is under internal pressure when it is in use or not.
2. Description of Related Art
It is known to use electronic systems to monitor certain parameters of a tire, for example the inflation condition, the inflation pressure or the temperature of the tire. If the electronic system is to be fixed to the tire, several means of fixing may be considered. Some known means use a connecting element of flexible material, intended to act as an interface between the tire (which is flexible) and the electronic system (which is rigid). In the text below, this connecting element will be called a “patch”.
The patch can fulfill a number of functions, two of which are particularly important: it fixes the electronic system to the tire, and it protects it from the deformations undergone by the tire.
By way of example, documents U.S. Pat. No. 6,462,650, WO 03/076216, US 2005/0076982 and US 2005/0076992 disclose a patch glued to the inner surface of the tire. The flexibility of the patch, which results from the material selected therefor and its geometry (see in particular US 2005/0126668), makes it possible to prevent the electronic system from being deformed and to limit the stresses transmitted thereto; this decoupling contributes to extending its operative life. More patches aiming at mechanical decoupling of electronic systems from tires are disclosed in DE 199 40 086, US 2005/076992 and US 2006/0237109.
Another known means of fixing an electronic system consists in sliding it into a kind of “pocket” made in the tire previously. US 2005/0217774 describes a solution of this kind. This configuration has the advantage of eliminating the phase of gluing the patch. It can be used, in particular, for systems for measuring pressure and temperature.
Another means of fixing comprises a patch which is designed not to completely isolate the electronic system or the sensitive part thereof from the tire but, in contrast, to amplify the deformations or rates of deformation to which a sensitive element of the electronic system is subjected. This is the case, for example, in onboard power generation systems such as a system in which a piezoelectric film is connected to the tire by way of a structure which amplifies certain deformations or the rates of deformation. US 2006/006728 is an example of such a patch